Recessed dilator-sheath assembly and method

Abstract

An introducer set (20) including a sheath (21) and dilator (30) is formed within a heated mold (60) to form a smooth external shape on the set. The distal end (22) of the sheath (21) is embedded in the dilator (30) and also formed at an angle (41) oblique to the longitudinal axis (42) of the introducer set (20). This construction permits the sheath (21) to be inserted into the body with a minimum of trauma to the patient and also permits easy removal of the sheath (21) from the dilator (30).

THE INVENTION CLAIMED IS: 
     
       1. A dilator-sheath assembly comprising: a sheath having one end adapted to be inserted in the body;   a dilator within said sheath and having a distal end extending beyond the one end of the sheath, said dilator having a recess within which said one end of said sheath is received whereby said dilator shields said one end of said sheath when the dilator-sheath assembly is inserted in the body, said dilator having an annular spur extending around said dilator and contiguous to said one end of said sheath, said spur defining said recess.   
     
     
       2. The dilator-sheath assembly of claim 1 wherein said one end of said sheath is externally tapered. 
     
     
       3. A dilator-sheath assembly comprising: a sheath having one end adapted to be inserted in the body;   a dilator within said sheath and having a distal end extending beyond the one end of the sheath, said dilator having a recess within which said one end of said sheath is received whereby said dilator shields said one end of said sheath when the dilator-sheath assembly is inserted in the body;   said sheath and dilator having longitudinal axes and being coaxial, said one end of said sheath being formed at an angle oblique to the longitudinal axis of said sheath and said dilator whereby rotation of said dilator and said sheath relative to one another about said axes disengages said one end of said sheath from said dilator recess.   
     
     
       4. A dilator-sheath assembly comprising: a sheath, said sheath being compatible for insertion within the body and having one end adapted to be inserted in the body;   a dilator within said sheath and having a distal end extending beyond the one end of said sheath; and   a transition means defined by an increase in the outer diameter of said dilator such that the outer diameter of said dilator is approximately equal to the outer diameter of said sheath at the one end of said sheath; and   wherein said transition means includes a continuous annular spur disposed about said dilator so that said one end of said sheath is received under said continuous annular spur.   
     
     
       5. A dilator-sheath assembly comprising: a sheath, said sheath being compatible for insertion within the body and having one end adapted to be inserted in the body;   a dilator within said sheath and having a distal end extending beyond the one end of said sheath; and   a transition means defined by an increase in the outer diameter of said dilator such that the outer diameter of said dilator is approximately equal to the outer diameter of said sheath at the one end of said sheath; and   wherein said one end of said sheath is externally tapered.   
     
     
       6. A dilator-sheath assembly comprising: a sheath formed of flexible plastic material, said sheath being compatible for insertion within the body and having one end adapted to be inserted in the body;   a dilator within said sheath and having a distal end extending beyond said one end of said sheath, said dilator being formed of flexible plastic material;   a transition means defined by an increase in the outer diameter of said dilator such that the outer diameter of said dilator is approximately equal to the outer diameter of said sheath at said one end of said sheath; and   wherein said one end of said sheath is formed to an angle oblique to the longitudinal axis of said sheath, and further in which said transition means is formed at an angle oblique to the longitudinal axis of said dilator so that said one end of said sheath is contiguous with said transition means.